drivers/usb/core/usb-acpi.c

   1 /*
   2  * USB-ACPI glue code
   3  *
   4  * Copyright 2012 Red Hat <mjg@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation, version 2.
   9  *
  10  */
  11 #include <linux/module.h>
  12 #include <linux/usb.h>
  13 #include <linux/device.h>
  14 #include <linux/errno.h>
  15 #include <linux/kernel.h>
  16 #include <linux/acpi.h>
  17 #include <linux/pci.h>
  18 #include <linux/usb/hcd.h>
  19
  20 #include "hub.h"
  21
  22 /**
  23  * usb_acpi_power_manageable - check whether usb port has
  24  * acpi power resource.
  25  * @hdev: USB device belonging to the usb hub
  26  * @index: port index based zero
  27  *
  28  * Return true if the port has acpi power resource and false if no.
  29  */
  30 bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
  31 {
  32         acpi_handle port_handle;
  33         int port1 = index + 1;
  34
  35         port_handle = usb_get_hub_port_acpi_handle(hdev,
  36                 port1);
  37         if (port_handle)
  38                 return acpi_bus_power_manageable(port_handle);
  39         else
  40                 return false;
  41 }
  42 EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
  43
  44 /**
  45  * usb_acpi_set_power_state - control usb port's power via acpi power
  46  * resource
  47  * @hdev: USB device belonging to the usb hub
  48  * @index: port index based zero
  49  * @enable: power state expected to be set
  50  *
  51  * Notice to use usb_acpi_power_manageable() to check whether the usb port
  52  * has acpi power resource before invoking this function.
  53  *
  54  * Returns 0 on success, else negative errno.
  55  */
  56 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
  57 {
  58         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  59         struct usb_port *port_dev;
  60         acpi_handle port_handle;
  61         unsigned char state;
  62         int port1 = index + 1;
  63         int error = -EINVAL;
  64
  65         if (!hub)
  66                 return -ENODEV;
  67         port_dev = hub->ports[port1 - 1];
  68
  69         port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
  70         if (!port_handle)
  71                 return error;
  72
  73         if (enable)
  74                 state = ACPI_STATE_D0;
  75         else
  76                 state = ACPI_STATE_D3_COLD;
  77
  78         error = acpi_bus_set_power(port_handle, state);
  79         if (!error)
  80                 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
  81         else
  82                 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
  83
  84         return error;
  85 }
  86 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
  87
  88 static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
  89         acpi_handle handle, int port1)
  90 {
  91         enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
  92         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  93         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  94         struct acpi_pld_info *pld;
  95         union acpi_object *upc;
  96         acpi_status status;
  97         int ret = 0;
  98
  99         if (!hub)
 100                 return 0;
 101
 102         /*
 103          * According to ACPI Spec 9.13. PLD indicates whether usb port is
 104          * user visible and _UPC indicates whether it is connectable. If
 105          * the port was visible and connectable, it could be freely connected
 106          * and disconnected with USB devices. If no visible and connectable,
 107          * a usb device is directly hard-wired to the port. If no visible and
 108          * no connectable, the port would be not used.
 109          */
 110         status = acpi_get_physical_device_location(handle, &pld);
 111         if (ACPI_FAILURE(status))
 112                 return -ENODEV;
 113
 114         status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
 115         upc = buffer.pointer;
 116         if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
 117                 || upc->package.count != 4) {
 118                 ret = -EINVAL;
 119                 goto out;
 120         }
 121
 122         if (upc->package.elements[0].integer.value)
 123                 if (pld->user_visible)
 124                         connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
 125                 else
 126                         connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
 127         else if (!pld->user_visible)
 128                 connect_type = USB_PORT_NOT_USED;
 129         hub->ports[port1 - 1]->connect_type = connect_type;
 130
 131 out:
 132         ACPI_FREE(pld);
 133         kfree(upc);
 134         return ret;
 135 }
 136
 137 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 138 {
 139         int port1;
 140         struct usb_device *udev;
 141         acpi_handle *parent_handle;
 142
 143         /*
 144          * In the ACPI DSDT table, only usb root hub and usb ports are
 145          * acpi device nodes. The hierarchy like following.
 146          * Device (EHC1)
 147          *      Device (HUBN)
 148          *              Device (PR01)
 149          *                      Device (PR11)
 150          *                      Device (PR12)
 151          *                      Device (PR13)
 152          *                      ...
 153          * So all binding process is divided into two parts. binding
 154          * root hub and usb ports.
 155          */
 156         if (is_usb_device(dev)) {
 157                 udev = to_usb_device(dev);
 158                 port1 = udev->portnum;
 159                 if (udev->parent) {
 160                         struct usb_hub *hub;
 161
 162                         hub = usb_hub_to_struct_hub(udev->parent);
 163                         /*
 164                          * According usb port's connect type to set usb device's
 165                          * removability.
 166                          */
 167                         switch (hub->ports[port1 - 1]->connect_type) {
 168                         case USB_PORT_CONNECT_TYPE_HOT_PLUG:
 169                                 udev->removable = USB_DEVICE_REMOVABLE;
 170                                 break;
 171                         case USB_PORT_CONNECT_TYPE_HARD_WIRED:
 172                                 udev->removable = USB_DEVICE_FIXED;
 173                                 break;
 174                         default:
 175                                 udev->removable = USB_DEVICE_REMOVABLE_UNKNOWN;
 176                                 break;
 177                         }
 178
 179                         return NULL;
 180                 }
 181
 182                 /* root hub's parent is the usb hcd. */
 183                 return acpi_find_child_device(ACPI_COMPANION(dev->parent),
 184                                 port1, false);
 185         } else if (is_usb_port(dev)) {
 186                 struct usb_port *port_dev = to_usb_port(dev);
 187                 struct acpi_device *adev = NULL;
 188
 189                 /* Get the struct usb_device point of port's hub */
 190                 udev = to_usb_device(dev->parent->parent);
 191                 port1 = port_dev->portnum;
 192
 193                 /*
 194                  * The root hub ports' parent is the root hub. The non-root-hub
 195                  * ports' parent is the parent hub port which the hub is
 196                  * connected to.
 197                  */
 198                 if (!udev->parent) {
 199                         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 200                         int raw;
 201
 202                         raw = usb_hcd_find_raw_port_number(hcd, port1);
 203                         adev = acpi_find_child_device(ACPI_COMPANION(&udev->dev),
 204                                         raw, false);
 205                         if (!adev)
 206                                 return NULL;
 207                 } else {
 208                         parent_handle =
 209                                 usb_get_hub_port_acpi_handle(udev->parent,
 210                                 udev->portnum);
 211                         if (!parent_handle)
 212                                 return NULL;
 213
 214                         acpi_bus_get_device(parent_handle, &adev);
 215                         adev = acpi_find_child_device(adev, port1, false);
 216                         if (!adev)
 217                                 return NULL;
 218                 }
 219                 usb_acpi_check_port_connect_type(udev, adev->handle, port1);
 220                 return adev;
 221         }
 222
 223         return NULL;
 224 }
 225
 226 static bool usb_acpi_bus_match(struct device *dev)
 227 {
 228         return is_usb_device(dev) || is_usb_port(dev);
 229 }
 230
 231 static struct acpi_bus_type usb_acpi_bus = {
 232         .name = "USB",
 233         .match = usb_acpi_bus_match,
 234         .find_companion = usb_acpi_find_companion,
 235 };
 236
 237 int usb_acpi_register(void)
 238 {
 239         return register_acpi_bus_type(&usb_acpi_bus);
 240 }
 241
 242 void usb_acpi_unregister(void)
 243 {
 244         unregister_acpi_bus_type(&usb_acpi_bus);
 245 }